As a display device used for visually displaying information or data on a computer monitor, a television receiver, or the like, display devices such as a liquid crystal display (LCD) and an organic light emitting display (OLED) have been widely used. Generally, the LCD or the OLED has a quadrangular shape such as a squared shape or a rectangular shape.
Meanwhile, a smart watch such as a Galaxy Gear (registered trademark) that may put on a wrist, or the like has appeared in recent years. However, the smart watch or the like also uses a substantially quadrangular display device as a display part.
On the other hand, a demand for a display device using a circular display part having a feeling like the existing analog watch by getting out of the uniform shape such as the quadrangular shape has been increased.
As the circular display device, there is a technique described in Patent Document 1. FIG. 1 is a view schematically showing a conventional circular liquid crystal display device.
As shown in FIG. 1, a conventional circular liquid crystal display device 100 includes: a first circular substrate 110 and a second circular substrate 120 adhered to each other with a liquid crystal layer interposed therebetween, wherein an image is displayed on the first circular substrate 110; a circular display part 111 in which liquid crystal cells are arranged; and first and second non-display parts 102a and 102b which have pad parts disposed therein to receive various control signals, image signals and a driving voltage that are required to display the image applied thereto, and are formed at a central portion and a peripheral portion of the circular display part 111.
The circular display part 111 of the first circular substrate 110 includes a plurality of pixel areas P formed at an area in which a plurality of gate lines GL and a plurality of data lines DL intersect. In a case of the plurality of gate lines GL, lines thereof having a circumference smaller than that of the circular display part 111 are arranged in a row from a boundary portion of the circular display part 111 to the central portion, and in a case of the plurality of data lines DL, lines thereof are arranged so as to traverse across the central portion of the circular display part 111. The pixel areas P, which are defined by the gate and data lines, have an inverse trapezoidal shape in which a length of an upper side is long and a length of a lower side is short.
Further, each of the pixel areas P includes thin film transistors T formed at portions in which the gate lines GL with the data lines DL intersect to switch the liquid crystal cells, and pixel electrodes (not shown) connected to the thin film transistors T to drive the liquid crystal cells.
The first non-display part 102a of the first circular substrate 110 is provided with a gate pad part GP that is connected to the gate line GL to supply a scanning signal supplied from a gate driver integrated circuit to the gate line GL, and the second non-display part 102b is provided with a data pad part DP that is connected to the data line DL to supply image information supplied from a data driver integrated circuit to the data line DL.
However, the display device of the above Patent Document 1 has a problem in that the gate line GL and the data line DL need to have a circular shape, an in particular, the pixel area P forming the display part of the display device needs to have an inverse trapezoidal shape in which the length of the upper side is long and the length of the lower side is short. Therefore, it is very difficult to form the pixel area P having the inverse trapezoidal shape and form the gate line GL and the data line DL having a circular shape, in the manufacturing process of the display device.
Further, as another prior art related to the circular display device, there is a technique described in Patent Document 2. FIG. 2 is a schematic view showing another conventional circular display device.
The conventional circular display device as shown in FIG. 2 is a rollerable type circular display device 200 which includes: a circular display part 220 that may be unfolded in two dimensions between a housed state and an unfolded state; and a housing 210 for winding the circular display part 220 in the housed state. Herein, the circular display part 220 is wound around a cone rotatably formed within the housing 210 while being disposed on the same shaft within the housing 210, and a state in which the circular display part 220 is housed within the housing 210 by being wound around the cone becomes the housed state, whereas a state in which the circular display part 220 is unfolded to an outside of the housing 210 by being unwound from the cone as shown by an arrow in FIG. 2, and thereby becoming a state that may be viewed from the outside as a whole, that is, the unfolded state shown in FIG. 2.
Further, the conventional circular display device of another prior art disclosed in Patent Document 2 has the same form as the Patent Document 1 in terms of the shape and disposition of the pixel area, and the disposition of the gate line and the data line.
Therefore, the circular display device of the Patent Document 2 has the same problem as the Patent Document 1 as described above.
In addition, the circular display device of the Patent Document 2 has two states, that is, the state in which the circular display part is housed and the state in which the circular display part is unfolded, and the circular display device is used with being unfolded in the unfolded state (state of FIG. 2) when using as the display device, and needs to be housed in the housed state when not using as the display device. Therefore, the circular display device has a problem in that it may be complicated in use and a configuration thereof for switching to the two states could be complicated.
Further, the circular display device of Patent Document 2 has a problem in that it may not be used as a purpose like the smart watch, for example.